Strip-collapsing device for sewing machines



J. E. ACKERMAN STRIP-COLLAPSING DEVICE FOR SEWING MACHINES Nov. 24, 1 953 2 Sheets-Sheet 1 Filed March 27, 1951 SWEE.

k H k.

kamay Zlhvembo? James E Acberman Q1... A. mw

& s

Nov. 24, 1953 J cK M 2,660,139

STRIP-COLLAPSING DEVICE FOR SEWING MACHINES Filed March 27, 1951 2 Sheets-Sheet 2 James E. Ackerm/an/ W aw i [M [AZ/1 Patented Nov. 24, 1953 STRIP-COLLAPSING DEVICE FOR SEWING MACHINES James E. Ackerman, Devon, Conn, assigncr to The Singer Manufacturing Company, Elizabeth, N. J a corporation of New Jersey Application March 27, 1951, Serial No. 217,835

9 Claims.

1 This invention relates to attachments for sewing machines and more particularly to improvements in sewing machine attachments of the strip-collapsing type.

In the production of seams in which a reinforcing fabric strip is included, as for instance,

the seam between the bib and trousers portion of an overall or similar garment, it is desirable that the reinforcing strip be severed short of the edge of the garment at each side so that a neater side hem may be formed in which the reinforcing strip is not included.

Strip-collapsing devices, of which the present invention is an improvement, include those devices which are operative at the will of the sewing machine operator usually by means of an actuating linkage carried by the sewing machine to urge each side of the reinforcing strip to a position out of the line of securing stitches, thereby eliminating the tedious and time consuming necessity for removing stitches before severing the reinforcing strip short of the garment edge.

It is an object of this invention to provide a strip-collapsing device associated with the workguiding devices as a unitary assembly, which is constructed so as to be applied to and removed from a sewing machine in a manner far more convenient than existing devices of this nature.

It is a further object to provide a unitary strip-collapsing device of the above removable and replaceable nature in combination with an actuating mechanism carried by the sewing machine frame, the parts of the strip-collapsing device and the actuating mechanism arranged in a novel fashion so as to provide a separable connection therebetween which is effective upon positioning of the unitary strip-collapsing device on the sewin machine.

Still another object of this invention is to provide in an actuating linkage for a strip-collapsing device of the above character a means for adjusting the extent or stroke of strip collapsing movement at each side of the strip and at the same time retaining the arrangement whereby the connection between the strip-collapsing device and the actuating linkage will be effective upon positioning of the unitary stripcollapsing device on the sewing machine regardless of the position of adjustment of the actuating linkage.

With these and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts described in connection with the accompanying drawings, which illustrate a preferred embodiment and in which:

. Fig. 1 is a front elevational view of a portion of a sewing machine having my invention applied thereto,

Fig. 2 is a fragmentary sectional view taken substantially along line 22 of Fig. 1,

Fig. 3 represents a bottom plan View of the unitary strip-collapsing device,

Fig. i represents a fragmentary side elevation of a portion of the actuating linkage, viewed as in Fig. 1 but illustrating a modified form of the adjustable connection,

Fig. 5 represents a top plan View of a portion of the sewing machine having my invention applied thereto and in which parts have been broken away to more clearly illustrate the invention,

Fig. 6 is a sectional view of part of the invention taken substantially along line B6 of Fig. 5, showing the manner in which the strip collapsing members are supported and arranged with respect to the slide-plate,

Fig. 7 represents a perspective view of the strip collapsing finers and the connection between the strip collapsing fingers and the actuating linkage showing particularly the relation of these parts with respect to the fabrics being stitched which are illustrated in dot-dash lines, and

Fig. 8 is a fragmentary elevational view of the delivery end of the attachment and the strip collapsing members with the work-pieces in section, showing, in full lines, the facing strip in normally extended condition and, in dotted lines, the strip-collapsing members in strip-collapsing position with the facing strip gathered between them so as to be confined in a space less than the needle gauge of the sewing machine.

In the selected embodiment illustrated in the drawings, the invention is shown as applied to a sewing machine of the type having a frame including a bed In of which the upper surface forms a work support ll. A standard I2 rises from the bed and supports an overhanging bracket-arm M from the extremity of which a presser-foot I5 is suspended and a needle bar 15 is journaled for reciprocatory motion. Needles ll carried by the needle bar cooperate with the complemental lower stitch forming mechanism (not shown) arranged beneath the work support in the formation of stitches. The needles also cooperate with feed dogs l8 which are operative through slots IS in a throat plate 2!} to advance the work past the stiching point. The work support I! is formed with an opening 2! in advance of the stiching point which provides access to the lower stitch forming n echanism as, for instance, for threading the loopers in the case of the illustrated chain stitch sewing machine, or for bobbin replacement if a lockstitch machine 5 were to be used.

As shown most; clearlyrin Figs.1.22and '5,"" work. guiding devicesfor forming a seam' including a reinforcing strip, together with a mechanism for collapsing the strip, are supported as a unitary assembly from a slide-plate 22 whichsisprovided. with spring clips 2323 adapted to embraceethee. work support H at the sides of the opening 2! to frictionally maintain the;..slide-plate-=in"the access opening.

Overlying the slide-plate 22 is a sheet metal covering plate 24 which is arrangeddnspaced: relation to the slide-plate by means of a spacing block 25; both the covering plate and the spacing block being secured in place on the slide-plate 22 as-by soldering, b'razing: etc. onctheupper surface of the covering plate, anedge guide-I-Zii is secured by means of fasteningscrews 27-21. To the-edge guide 26; in turn; an edge folding; guide 28 is secured by means of screws -.2929. As best shown in'Fig; 8, theedgeguide and the edge folding guide are arranged todirect'the marginal 'edges of tWO panelsRAand B, respectively, of body fabrics *which :are to be stitched. together so as toformrareinforced seam.

Fig; 8 also 'illustratesxin': full. lines the :relative positions of. a reinforcing striprS vasit is normally delivered from a tubular strip'igui'de' 30 which is form'ed at itsi'delivery'endwvith scrolls 3 l--3 l in order to inturn' the imarginalilrawiedges 10f thestripp To accommodate. the 'istrip-guide' in" an 'upwardly inclined positiontbeneathrthe slideplate 22, the slide-plate is provided on each-side at its forward extremity with downturnedears 32-32; to which. is'securedxby fastening screws 33- 33 *ax-U-shaped guideesupportm'gyoke meme. berth The strip=guide tlli'betweeniitsiends :.-is;. provided with laterallyex-terrding 'ears:35:-il-5 which "the guide is secured to the: yoke: member by .the -SCIWSJ35f-3E. The slideeplate :ZZL-atitsforwardaedgezis recessed; as .atfl, toiaccommo-idate the sdeli'viery end of the stripsguide;

In" the normal operationxof the ebodyl fabric" guides and'reinforcing'stripiguide as described above, the 'fabrics :are directed; to ':the stitching point "in. 1 the relationship as: illustrated ini-the dot-dash linesofFig. 7." With speciahregard to. the reinforcing strfip,. itiwill .beinoteclithat .the' inturned edge portionsnormally are directedeach to'the 'path' of'one or'more' needles; When in a subsequent operation, the reinforcing" strip must be severedshort Ofthe-edge of a garment; it is advantageous'that =the stripbe' free of "thestitches from-the point at which? it is severed to the'edge of the'garmentybecause'if not; these stitches must 'be removed by a tedious and timeconsuming hand" operation.

In' the present invention; a" new and improved: construction isprovided .forrat' will "shifting "or: apsin the strip ata point between them; delivery end 'of'the strip-guide andtheneedles; to a sidewise gathered positioni'in 'whichthe strip' will be excluded 'fromthe lines of stitches being formed. To this end, opposed strip-engaging members, indicatedgenerallyas 38 and 38', each of the oppositeh'and are arranged in'th'e space between'the slide-plate 22 and the sheet metal covering plate 24 and are'adaptedto be manually shifted so that they 'relativelyapproach eachother and' thereby collapse the strips between them. A detailed description of one of the stripengaging members will sufiice, since the comparable opposing members are identical and merely reversed in position. In the drawings, the base numbers, generally 38 through 5i, apply to parts of the right hand strip-engaging mem b'ersxas viewed in Fig. 1,.whilethe prime numbers refer tocomparable parts of the left hand stripengaging member.

The strip-engaging member 33 comprises a flat .baseeplatev39 which is disposed to underlie thezslideeplate 22. A rectangular slide-block extends upwardly from the plate 39 and is adaptedto enter-a guide-slot 4! formed in the slide plate22 which confines the slide-block for translatory movement laterally of the strip guide 30. Therflat'tbaseeplate :38 is formed with an ear 52 to which is secured a wire spring 53 that is held in place on'the slide-plate 22 by a screw 4%. The spring 43 biases the strip-engaging members 38- -38 apart into what is termed .a normal. re-

tracted positiom. a: position: determined by the ends'of'theguide .slot 6! in the slide-plate Carried above the slideplate 22 is a U-shaped member 450i whichwone limb 46 is slotted as at 4'! tolaccommodate fastening screws 48l8' by which the 1U-shaped member is secured to the slide-block .46 forconvenient lateral adjustment to a wide range of retracted positions to accommodate a variety of strip widths or bodily shif ing of .the strip;

As clearly illustrated in Fig. 6, the limb -56 of the'U-shap'ed member Q5 and the base-plate 39 extendbeyond opposite sides of the slide-block 68 so as to'lock the strip-collapsing mechanism in place-on'the slide-plate 22. The free end of the Ueshaped member 5 is formed with a laterallyjextending finger d9 whichis disposed between:

the .deliveryend. of the strip-guide Bil and the needles :Il; The free extremity of thefinger isshouldered .to provide. a .vertical stripe-engaging surfaceiil "and afiat overhanging extension 5!;

The leading edge of the vertical strip engaging surface. 5ll is beveled as atlEZ to permit smooth passage-of the strip. past the fingers;

In.'..usua1 practice and as illustrated clearly in Fig; 7, the strip-engaging members are'adjusted by means of screws it- 5 so that when in normalzretracted position the strip engaging surface' es just clears the edge of the strip as it emerges from the strip-guide. In this position, it will be-appreciated that the strip-engaging members present no obstruction nor do they hinderinitial insertion of the strip in any manner.

lhe means by which the above described right and left hand strip engaging members 33 and 38 may be moved simultaneously into operative po-- sitionwill now be described. As illustrated in Fig. 1, the actuating means comprises generally a'linkage carried by the bed ii) and including a lever use fulcrumed by the pivot screw 53 which secures the lever to the bed. At one side of the screw 53, a longitudinally slidable bar "i is pivotallyconnected to the lever by a pin 55. A second longitudinally slidable bar 5% is pivotally connected to 'thelever at the opposite side of the fulcrum by a pivot-pin The slide-bar 55 and the pivot-pin connection 57 with the lever are constructed in a novel manner as will be de scribed below to permit a particularly advantageous adjustment of the relative movements imparted'by the linkage.

In order that the strip-engaging'members and the other parts carried by the slide-plate may be conveniently removed and replaced, readily separable connections are provided between the slide-bar 54 and the strip-engaging member 38 and between the slide-bar 56 and member 38'. The separable connections each comprise complemental coupling means arranged to interengage in positive driving connection when the slide-plate 22 is properly positioned in the access opening of the work-plate. Referring particularly to Fig. 7, the base-plate 35 of the right hand strip-engaging member 38 is formed with a short extension 58 to which is fixed a rod 59 which extends laterally through a guide notch 60 formed in the downturned ear 32 of the slide-plate. The rod 59 is formed at its free extremity with spaced shoulders 6i and E2 to provide one part of the separable coupling with the slide-bar 5-4. Secured to the bar 58 by means of a fastening screw 63 and a locating pin 64 is a coupling member 65 having outwardly extending jaw members (it and 61 defining an opening or notch 68 which is adapted to engage the rod 59 between the spaced shoulders 6i and 62 when in operative position. The free extremity of each jaw member is inclined as at 6% so as to properly admit the rod 59. despite slight misalignment due to manufacturing tolerances etc.

The separable connection between the left hand strip-engaging member 38' and the slide-bar 55 is similar to the above described connection. Base-plate 39' is formed with a long lateral extension lfi to which is fixed a rod H which extends laterally through a guide notch Eil in the downturned car 32 and is formed at its free extremity with spaced shoulders 13 and Hi. The slide-bar 56 is provided with a coupling member 15 which is identical with coupling member 65 and is secured to the slide-bar 56 in the same manner. The guide notches t and 50 of the downturned ear 32 are closed by a notched keeper 12 secured to the downturned ear so as to slidingly confine both of the rods 59 and H in place on the slide-plate.

It will be appreciated that the separate connections of the preferred embodiment are susceptible of modification within the spirit of the above disclosure. As an instance, the jaw members defining a notch or opening may be carried by the strip-engaging members and the complemental rod formed as part of the slide-bar.

In order for the rods 59 and H properly to re- ".1

engage the coupling members 55 and 15, respectively, upon replacement of the slide-plate into the access opening of the work-plate, the actuating linkage is biased by a Spring 76, which is arranged between the bed Ill and the lever 52, into a normal retracted position as determined by the strip block H. In this normal retracted position, the notches $8 of the coupling members are disposed laterally coincident with the lateral position in which the shouldered extremities of the rods 59 and ii are biased by the spring (.13. In addition, a bracket l8 which is secured to the bed iii, is provided with a vertical projection i9 which is spaced from the bed to define a guide slot in which both slide-bars dand 56 are con-- fined. When the slide-plate is removed, the bracket projection is serves to support the slidebars so that the vertical position of the bars remains substantially the same. The inclined surfaces '69 of the jaws being sufiicient to accommodate a reintroduction of the rods so and H despite any slight change of vertical position of the jaws. A connection between the lever 1G3 and a foot treadle or a knee shifter device or the like may be made in any desired fashion; a rod 80 is illustrated in Fig. 1 for this purpose. A stop member 8| adjustably secured to the bed i0 limits the operative movement of the lever Hill in response to actuation by the rod. 89. As the lever is turned, the slide-bars 54 and 56 will be moved in opposite directions and by means of the coupling connection will impart simultaneous stripcollapsing movements to the opposed strip-engaging members.

In the specific embodiment illustrated in the drawings, it will be noted that three needles areemployed, and as shown in Fig. '7, two of the needles are arranged to penetrate the left hand edge of the reinforcing strip while a single needle is disposed so as to penetrate the right hand edge. It necessarily follows, therefore, that the left hand strip-engaging member 38 must be moved a greater distance than the right hand member 38 in order for both edges of the strip to be moved into needle avoiding position. As illustrated in Fig. 1, the position of the pin 55 which connects bar 54 to the lever Hill is disposed nearer the pivot screw 53 of the lever than the connection of the bar 56 with the lever. It will be apparent therefore that the stroke of .bar 56 will exceed that of bar 54 in proportion to the difference in distance between the lever connections therewith and the pivotal axis of the lever.

It is frequently desirable to change the stroke of one or both of the strip-engaging members, as for instance, if the number of needles at either side of the strip is changed. The instant construction provides such an adjustment of stroke in a novel and advantageous manner such that the extreme position of the parts remains unchanged. To this end, a link 82 is interposed between the lever I00 and the bar 55. A clamp screw 83 connects the link with the bar and may be tightened to secure the link in any desired fixed angular position with respect to the bar. It will be apparent, therefore, that the link 82 when so clamped forms with the bar 56 in effect a single solid connection between the pivot-pin 51 and the coupling member if). A slot 84 is formed in the lever to accommodate a pivotal connection 51 with link 32. Fig. 4 illustrates a construction in which the slot 35 is arcuate, the center of curvature corresponding to the axis of the clamp screw 83 when the bar 56 is disposed in normal retracted position. It will be appreciated that with such an arcuate slot, a full range of adjustment of the link is possible without disturbing the spring biased extreme position of the bars 54 and 56.

In a modified form of construction illustrated in Fig. l, the slot 85 is straight; however, it is formed along a line tangent to the arc formed by movement of the pivotal connection 51 about the axis of the clamp screw 83; in other words, the straight slot of Fig. 1 is formed to closely approximate the arcuate slot of Fig. 4. The straight slot is preferably for manufacturing economy and it is pointed out that, since the straight slot is tangent to the ultimately desired arc, only a slight shifting of the bar 58 is involved, this being compensated for by the inclined surfaces 69 of the jaws.

Having thus set forth the nature of the invention, what I claim herein is:

1. A strip-collapsing attachment for sewing machines comprising a supporting plate, means securing said supporting plate to said sewing machine for ready removal and replacement, work-guides including a strip-guide carried by said supporting plate, said plate having clon gated slots formed therein transversely of said strip-guide, a pair of slide-blocks arranged in said slots, a strip-engaging member secured at one side of each of said blocks, actuating mechanism carried by said sewing machine for imparting strip collapsing movements to said stripengaging m mbers, and means secured at the opposite side of each of said blocks disposed in operative relation with said actuating mechanism when said supporting plate is replaced on said sewing machine.

2. In a sewing machine having a frame including a work-support with an access opening therein, a strip-collapsing attachment comprising a cover-plate removably secured on said work-support in said access opening, workguiding means including a strip-guide carried by said cover-plate, said over-plate having an elongated slot formed therein transversely of said strip-guide, two slide-members disposed at one side of said cover-plate, said members each being formed with a slide-block disposed to enter said transverse cover-plate slot, opposed stripengaging members each secured to one of said slide-blocks at the opposite side of said coverplate from said slide-members, and means carried by said sewing machine frame for at will moving said slide-members in opposite directions.

3. In a strip-collapsing device for sewing machines, a work-guiding attachment including strip-guiding means, a strip-guide supporting member, and movable strip-collapsing members carried by said strip-guide supporting member, said attachment constructed for ready removal and replacement on said sewing machine, a mechanism carried by said sewing machine for imparting movement to said strip-collapsing members, complemental coupling means formed on said strip-collapsing members and on said actuating mechanism, said coupling means disengageable upon removal of said attachment from the sewing machine and constructed and arranged to provide eiiective driving connection between each of said strip-collapsing members and said actuating mechanism when said workguiding attachment is positioned on said sewing machine.

4. In a strip-collapsing device for sewing machines, a work-guiding attachment including strip-guiding means, a strip-guide supporting member, opposed strip-collapsing members carried by said strip-guide supporting member for translatory movement transversely of said stripguide, and a first spring means biasing said stripcollapsing members into normal retracted positions, said attachment being constructed for ready removal from and replacement on said sewing machine, a linkage carried by said sewing machine for imparting movement to said strip-collapsing members in opposite directions, a second spring means biasing said linkage into normal retracted position, each of said stripcollapsing members and said actuating linkage being formed with complemental coupling surfaces to provide readily separable connections therebetween, said coupling surfaces being disposed to reengage upon replacement of said attachment on the sewing machine.

5. In a strip-collapsing device for sewing machines, a work-guiding attachment including strip-guiding means, a strip-guide supporting member, opposed strip-collapsing members carried by said strip-guide supporting member for translatory movement transversely of said stripguide, and a first spring means biasing said stripcollapsing members into normal retracted positions, said attachment being constructed for ready removal from and replacement on said sewing machine, a linkage carried by said sewing machine for imparting movement to said stripcollapsing members in opposite directions, a second spring means biasing said linkage into normal retracted position, each of said strip-collapsing members and said actuating linkage being formed with complemental coupling surfaces to provide readily separable connections therebetween, one of said complemental coupling surfaces of each separable connection comprising a projection, and the other of said coupling surfaces defining an opening arranged to accommodate said projection.

63. In a strip-guiding device for sewing machines, strip-guiding means, at least one movable strip-engaging member arranged at each side of said strip-guiding means, said strip-engaging members each having a stroke from normal re- 'racted position out of the path of said strip to a strip-collapsing position in the normal path of said strip, and an actuating mechanism for said strip-collapsing members, including a lever pivotally secured to said sewing machine, separate slide-bars disposed to transmit motion from said lever to each of said strip-engaging members, a link arranged between one of said slide-bars and said lever, clamp means adjustably securing said link to said slide-bar, a guideway formed on said lever, a guide element carried by said link and adapted to secure said link pivotally to said lever along said guideway at any selected one of a range of distances from the pivotal support of said lever to permit an independent adjustment of the stroke of one of said stripengaging members without disturbing said normal retracted position thereof.

'7. In a sewing machine having stitch-forming instrumentalities and work-guiding devices for producing a seam including a reinforcing strip, and means for at will collapsing said strip into a stitch-avoiding position, said mechanism including a pair of movable strip-engaging members disposed in normal retracted positions one at each side of said reinforcing strip, and a linkage carried by said sewing machine for at will shifting said strip-engaging members into strip-collapsing positions in the normal path of the reinforcing strip, said linkage including two lengthwise shiftable bars each connected at one end to a respective one of said strip-engaging members, and a lever pivotally carried by said sewing machine and provided with a connection with each of said bars to impart operative movement to said bars in opposite directions, one of said bars having a joint formed intermediate its ends, said joint having an axis about which the end portions of said bar may be angularly positioned, the connection between said jointed bar and sa d lever being adjustable to vary the strip-collapsing posi tion of one of said strip-engaging members without changing the normal retracted position thereof, said connection including a pivot-pin carried by said bar, an arcuate slot formed in said lever to adjustably accommodate said pivot-pin, the center of curvature of said arcuate slot corresponding with the axis of said bar joint when said strip-engaging members are disposed in normal retracted positions.

8. A device as set forth in claim 7, in which said lever is provided with a straight slot, said slot being arranged along a line which is tangent to the are formed by movement of said pivotpin about, the axis of said bar joint when said strip-engaging members are disposed in normal retracted positions.

9. In a sewing machine having stitch-forming instrumentalities and a work-support formed with an aperture providing access to said stitch-forming instrumentalities and adapted to accommodate a slide-cover plate, a strip-collapsing device including strip-guiding means, a strip-guide supporting plate interchangeably replaceable with the slide-cover plate in said work-support aperture, a pair of strip-engaging members slidably secured to said strip-guide supporting plate, means associated with said supporting plate confining said strip-engaging members for translatory movement transversely of said strip-guide, and actuating mechanism carried by said sewing machine for imparting strip-collapsing movements to said strip-engaging members, said mechanism including a pair of spaced members slidably secured to said sewing machine, and a linkage connecting said members for movement in opposite directions, and complemental coupling means providing an interlock between each of said strip-engaging members and a respective one of said actuating members, each of said coupling means comprising a projection extending from one of said members, the other of said members being formed with an apertured portion arranged to accommodate said projection when said attachment is slidably introduced in place in the work-support aperture of the sewing machine.

JAMES E. ACKERMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,371,600 Braf Mar. 15, 1921 1,422,808 Ringe July 11, 1922 1,555,006 Hagen Sept. 29, 1925 1,916,058 Maier June 27, 1933 1,946,359 Riviere Feb. 6, 1934 2,313,261 Podgorny Mar. 9, 1943 2,546,135 Reid Mar. 20, 1951 

